Rectification unit for stirling refrigerator

ABSTRACT

A stirling refrigerator may include a compressing portion compressing operating fluid filling a housing by reciprocal motion of a piston, an expanding portion expanding the operating fluid compressed at the compressing portion by reciprocal motion of a piston, and a regenerating portion fluidly communicating the compressing portion with the expanding portion, and may provide heat at the compressing portion and may absorb heat at the expanding portion through repeating isothermal compression, constant-volume process and isothermal expansion of the operating fluid. The rectification unit may be adapted to uniformalize flow of the operating fluid flowing between the compressing portion and the expanding portion.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority to Korean Patent Application No. 10-2012-0157477 filed on Dec. 28, 2012, the entire contents of which is incorporated herein for all purposes by this reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a rectification unit for a stirling refrigerator. More particularly, the present invention relates to a rectification unit for a stirling refrigerator which smoothes flow of operating fluid undergoing isothermal compression or isothermal expansion by reciprocal motion of pistons used at a compressing portion and an expanding portion in the stirling refrigerator.

2. Description of Related Art

Generally, an air conditioning system of a vehicle maintains a temperature in the vehicle to be a suitable temperature regardless of change in ambient temperature so as to maintain comfortable indoor environment.

Such an air conditioning system includes a compressor compressing coolant, a condenser condensing the coolant compressed at the compressor, an expansion valve quickly expanding the coolant condensed and liquefied at the condenser, and an evaporator evaporating the coolant expanded at the expansion valve and cooling air by using evaporative latent heat of the coolant. The air cooled by the evaporator is blown into a cabin in which the air conditioning system is mounted.

However, a conventional air conditioning system uses CFC/HCFC family compound as the coolant that is operating fluid. Since the CFC/HCFC family compound is chemically stable compound, it reaches the stratosphere in an undecomposed state when leaking into the atmosphere. In addition, it reacts with ultraviolet rays of the sunlight at the stratosphere such that chlorine atom is decomposed, and the chlorine atom reacts with ozone to generate chlorine monoxide. The chlorine oxide may destruct the ozone layer.

Recently, helium gas or nitrogen gas instead of the CFC/HCFC family compound is used as the operating fluid to prevent environmental pollution. In addition, stirling refrigerator using the helium gas or the nitrogen gas as the operating fluid is developing. According to the stirling refrigerator, the operating fluid is cooled to ultralow temperature through endothermic reaction occurring at isothermal expansion and the cooled operating fluid is used for cooling the vehicle by repeating isothermal compression, constant-volume process, isothermal expansion and constant-volume process of the operating fluid.

When the operating fluid flowing between a compressing portion and an expanding portion passes through a regenerating portion between the compressing portion and the expanding portion at the isothermal compression and the isothermal expansion of the operating fluid in the stirling refrigerator, however, the operating fluid may not flow smoothly by pressure imbalance in flow path of the operating fluid. Therefore, efficiency of the stirling refrigerator may be deteriorated.

The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

BRIEF SUMMARY

Various aspects of the present invention are directed to providing a rectification unit for a stirling refrigerator having advantages of achieving pressure balance when operating fluid flows and improving efficiency of the stirling refrigerator by smoothening flow of the operating fluid having undergone isothermal compression or isothermal expansion according to reciprocal motion of pistons applied to a compressing portion and an expanding portion of the stirling refrigerator.

In an aspect of the present invention, a rectification unit for a stirling refrigerator which may include a compressing portion compressing operating fluid filling a housing by reciprocal motion of a piston, an expanding portion expanding the operating fluid compressed at the compressing portion by reciprocal motion of a piston, and a regenerating portion fluidly communicating the compressing portion with the expanding portion, and provides heat at the compressing portion and absorbs heat at the expanding portion through repeating isothermal compression, constant-volume process and isothermal expansion of the operating fluid, may include a rectifier disposed at an end portion of a heat exchanger provided at the compressing portion or the expanding portion in the housing and rectifying the operating fluid flowing out from the compressing portion or the expanding portion and passing through the heat exchanger, and a fixing plate adapted to fix the rectifier at the end portion of the heat exchanger. wherein the rectification unit is adapted to uniformalize flow of the operating fluid flowing between the compressing portion and the expanding portion, and

The rectifier is formed by agglomerating a wire irregularly.

The fixing plate is provided with an insertion recess in which the rectifier is inserted.

The fixing plate is provided with a plurality of penetration holes penetrating the insertion recess, and wherein through the penetration holes, the operating fluid flows.

A sealing member is interposed between an exterior circumference of the fixing plate and an interior circumference of the housing.

A sealing member is interposed between a surface of the heat exchanger contacting with the fixing plate and the fixing plate.

The housing is provided with a slanted surface slanted toward the heat exchanger with respect to a flow hole through which the operating fluid flows in or out such that exhaust pressure is uniformalized when the operating fluid passing through the rectifier is exhausted.

The slanted surface is so slanted that a diameter of the slanted surface with respect to the flow hole becomes larger from the flow hole to the rectifier.

The fixing plate is fixed to the end portion of the heat exchanger by a snap ring mounted in an annular groove formed in the housing.

The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a stirling refrigerator using a rectification unit for the stirling refrigerator according to an exemplary embodiment of the present invention.

FIG. 2 is a partially cut-away perspective view of a stirling refrigerator using a rectification unit for the stirling refrigerator according to an exemplary embodiment of the present invention.

FIG. 3 is a partial cross-sectional view of the stirling refrigerator using a rectification unit for the stirling refrigerator according to an exemplary embodiment of the present invention.

FIG. 4 is an exploded perspective view of a rectification unit for a stirling refrigerator and a heat exchanger according to an exemplary embodiment of the present invention.

It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment.

In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing.

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that the present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.

An exemplary embodiment of the present invention will hereinafter be described in detail with reference to the accompanying drawings.

It is to be understood that exemplary embodiments described in this specification and the drawings are just some exemplary embodiments of the present invention and do not represent all the exemplary embodiments of the present invention, and thus various modifications and equivalent arrangements may exist in the filing date of the present invention.

FIG. 1 is a schematic diagram of a stirling refrigerator using a rectification unit for the stirling refrigerator according to an exemplary embodiment of the present invention, FIG. 2 is a partially cut-away perspective view of a stirling refrigerator using a rectification unit for the stirling refrigerator according to an exemplary embodiment of the present invention, FIG. 3 is a partial cross-sectional view of the stirling refrigerator using a rectification unit for the stirling refrigerator according to an exemplary embodiment of the present invention, and FIG. 4 is an exploded perspective view of a rectification unit for a stirling refrigerator and a heat exchanger according to an exemplary embodiment of the present invention.

Referring to FIG. 1, the stirling refrigerator using a rectification unit 10 according to an exemplary embodiment of the present invention is operated by a rotating shaft 103. The rotating shaft 103 receives driving torque from an engine of a vehicle through a pulley 101, and thereby is rotated. The stirling refrigerator includes a compressing portion 110 compressing operating fluid filling a housing 109 by reciprocal motion of a piston 107, an expanding portion 120 expanding the operating fluid compressed at the compressing portion 110 by reciprocal motion of a piston 107, and a regenerating portion 130 fluidly communicating the compressing portion 110 with the expanding portion 120.

The stirling refrigerator provides heat at the compressing portion 110 and temperature of the operating fluid rises. The heated operating fluid is regenerated at the regenerating portion 130 connected to the compressing portion 110 through a connecting pipe 140. After that, the expanding portion 120 absorbs heat from the operating fluid and cools the operating fluid to ultralow temperature. Providing heat, regeneration, and absorbing heat are achieved through isothermal compression, constant-volume process and isothermal expansion of the operating fluid.

Herein, the operating fluid which is cooled at the expanding portion 120 exchanges heat with another operating fluid circulating through a heat exchanger provided in a vehicle. Another operating fluid cooled through heat-exchange with the operating fluid cools the air discharging into a cabin of the vehicle. Thereby, air-conditioning of the vehicle may be achieved.

The pistons 107 are mounted at the rotating shaft 103 penetrating through the compressing portion 110 and the expanding portion 120. Therefore, if the operating fluid is compressed at the compressing portion 110, the operating fluid is expanded at the expanding portion 120. A predetermined angle is formed by the pistons 107, and the pistons 107 are mounted at the rotating shaft 103 through a pair of swash plates 105 provided respectively in the compressing portion 110 and the expanding portion 120.

In addition, the compressing chamber 111 and the expansion chamber 121 for compressing or expanding the operating fluid through reciprocal motion of the pistons 107 are formed in the compressing portion 110 and the expanding portion 120, respectively.

In addition, heat exchangers 150 provided at the housing 109 are included respectively in the compressing portion 110 and the expanding portion 120.

A rectification unit 10 for the stirling refrigerator according to an exemplary embodiment of the present invention is adapted to smoothen flow of the operating fluid having undergone the isothermal compression or the isothermal expansion by reciprocal motion of the pistons 107 provided in the compressing portion 110 and the expanding portion 120. Thereby, pressure balance is achieved when the operating fluid flows and efficiency of the stirling refrigerator is improved.

For these purposes, the rectification unit 10 for the stirling refrigerator according to an exemplary embodiment of the present invention, as shown in FIG. 2 to FIG. 4, includes a rectifier 11 and a fixing plate 13.

The rectifiers 11 are disposed at both end portions of the heat exchanger 150 and rectify the operating fluid exhausted from the compressing portion 110 or the expanding portion 120 and passing through the heat exchanger 150.

Herein, the rectifier 11 is formed by agglomerating a wire irregularly so as to uniformalize flow pressure of the operating fluid when the operating fluid flowing in the compressing portion 110 or the expanding portion 120 is exhausted from the compressing portion 110 or the expanding portion 120.

In addition, the fixing plates 13 fix the rectifiers 11 at both ends of the heat exchanger 150.

An insertion recess 15 for receiving the rectifier 11 disposed at the end of the heat exchanger 150 and a plurality of penetration holes 17 corresponding to the insertion recess 15 and flowing the operating fluid are formed at a surface of the fixing plate 13. The heat exchanger 150 is fluidly communicated with the compressing portion 110 or the expanding portion 120 through the penetration hole 17.

Therefore, the fixing plate 13 flows the operating fluid into the rectifier 11 and the heat exchanger 150 through the penetration hole 17. At this time, the flow pressure of the operating fluid is uniformalized when the operating fluid passes the rectifier 11. Therefore, the rectifier 11 smoothens the flow of the operating fluid.

A sealing member 19 may be interposed between an exterior circumference of the fixing plate 13 and an interior circumference of the housing 109.

In addition, a sealing member 19 may be interposed between a surface of the heat exchanger 150 contacting with the fixing plate 13 and the fixing plate 13.

The sealing members 19 prevent leakage of the operating fluid between the exterior circumference of the fixing plate 13 and the interior circumference of the housing 109 and between the fixing plate 13 and the surface of the heat exchanger 150.

The fixing plates 13 are mounted at both end portions of the heat exchanger 150 by snap rings 23 mounted at annular grooves 21 formed in the housing 109. Thereby, the fixing plates 13 are fixed in the housing 109.

In the present exemplary embodiment, the snap ring 23 fixes the rectifier 11 and the fixing plate 13 to the end portion of the heat exchanger 150 and also fixes the heat exchanger 150 in the compressing portion 110 or the expanding portion 120.

Meanwhile, a surface of the housing 109 is provided with a slanted surface 27 slanted toward the heat exchanger 150 with respect to the flow hole 25 through which the operating fluid flows in or out such that exhaust pressure is uniformalized when the operating fluid passing through the rectifier 11 is exhausted, in the present exemplary embodiment.

Herein, the slanted surface 27 is so slanted that a diameter of the slanted surface 27 with respect to the flow hole 25 becomes larger from the flow hole 25 to the rectifier 11.

Therefore, pressure of the operating fluid having passed through the heat exchanger 150 is uniformalized when passing through the rectifier 11 and then the operating fluid is exhausted from the rectifier 11. When the operating fluid is exhausted through the flow hole 25, the operating fluid is led along the slanted surface 27 such that uniform pressure is generated at the flow hole 25.

That is, when the operating fluid having passed through the rectifier 11 passes through the narrowing connecting pipe 140, the slanted surface 27 leads the operating fluid to pass the connecting pipe 140 with uniform pressure. Therefore, the slanted surface 27 as well as the rectifier 11 uniformalizes the pressure of the operating fluid to smoothen flow of the operating fluid.

If the rectification unit 10 for the stirling refrigerator according to an exemplary embodiment of the present invention is applied, the pressure of the operating fluid having undergone the isothermal compression or the isothermal expansion according to the reciprocal motion of the pistons 107 provided in the compressing portion 110 and the expanding portion 120 is uniformlized when the operating fluid passes through the heat exchanger 150. Therefore, flow of the operating fluid between the compressing portion 110, the expanding portion 120 and the regenerating portion 130 may be smoothened.

In addition, since smooth flow of the operating fluid is pressure-balanced when passing the connecting pipe 140 with a small diameter, compression ratio and expansion ratio of the operating fluid in the compressing portion 110 and the expanding portion 120 may be further improved. Therefore, efficiency of the stirling refrigerator may be improved.

For convenience in explanation and accurate definition in the appended claims, the terms “upper”, “lower”, “inner” and “outer” are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents. 

What is claimed is:
 1. A rectification unit for a stirling refrigerator which includes a compressing portion compressing operating fluid filling a housing by reciprocal motion of a piston, an expanding portion expanding the operating fluid compressed at the compressing portion by reciprocal motion of a piston, and a regenerating portion fluidly communicating the compressing portion with the expanding portion, and provides heat at the compressing portion and absorbs heat at the expanding portion through repeating isothermal compression, constant-volume process and isothermal expansion of the operating fluid, wherein the rectification unit comprises: a rectifier disposed at an end portion of a heat exchanger provided at the compressing portion or the expanding portion in the housing and rectifying the operating fluid flowing out from the compressing portion or the expanding portion and passing through the heat exchanger, and a fixing plate adapted to fix the rectifier at the end portion of the heat exchanger. wherein the rectification unit is adapted to uniformalize flow of the operating fluid flowing between the compressing portion and the expanding portion, and
 2. The rectification unit of claim 1, wherein the rectifier is formed by agglomerating a wire irregularly.
 3. The rectification unit of claim 1, wherein the fixing plate is provided with an insertion recess in which the rectifier is inserted.
 4. The rectification unit of claim 3, wherein the fixing plate is provided with a plurality of penetration holes penetrating the insertion recess, and wherein through the penetration holes, the operating fluid flows.
 5. The rectification unit of claim 1, wherein a sealing member is interposed between an exterior circumference of the fixing plate and an interior circumference of the housing.
 6. The rectification unit of claim 1, wherein a sealing member is interposed between a surface of the heat exchanger contacting with the fixing plate and the fixing plate.
 7. The rectification unit of claim 1, wherein the housing is provided with a slanted surface slanted toward the heat exchanger with respect to a flow hole through which the operating fluid flows in or out such that exhaust pressure is uniformalized when the operating fluid passing through the rectifier is exhausted.
 8. The rectification unit of claim 7, wherein the slanted surface is so slanted that a diameter of the slanted surface with respect to the flow hole becomes larger from the flow hole to the rectifier.
 9. The rectification unit of claim 1, wherein the fixing plate is fixed to the end portion of the heat exchanger by a snap ring mounted in an annular groove formed in the housing. 